The present invention generally relates to a novel quick connect electrical cable connector. More specifically, the invention relates to a novel in-line electrical cable connector for electrically connecting ends of an electrical cable.
Many different types of electrical cable connectors are available in the modem market. One type of electrical cable connector is an in-line connector which comprises releasably interconnectable, electrically conductive male and female portions. The male and female portions are connected to ends of electrical cables. By inserting the male portion into the female portion, the ends of the cables are electrically joined, thereby forming a single electrical conductor. Preferably, the male portion is removable from the female portion to allow for lengthening, replacement, servicing, etc. of the connector and/or the cable. Accordingly, in a preferred construction, the male and female portions are capable of repeated connections and disconnections.
One example of such a cable connector is disclosed in the U.S. Pat. No. 4,702,539 to Cusick, III et al. The connector comprises a male portion and a female portion coupled to ends of electrical cables. The male element has a projection releasably insertable into a bore in the female portion in order to electrically connect the ends of the cables. To provide a secure fit between the male and female portions, a mechanism is provided which draws the male portion into the female portion upon rotation of the male portion with respect to the female portion.
Specifically, the male portion has a spiral-like groove disposed along the circumference of the projection, and the female portion has a dimple which extends substantially radially into the bore. The projection of the male portion also includes a radially reduced or flattened segment which extends from a distal end of the projection to an edge of the groove. The flattened segment is recessed with respect to the circumference of the projection by a distance substantially equal to the distance between a surface of the bore in the female portion and a terminal end of the dimple.
To couple the male portion with the female portion, the projection is positioned with respect to the bore such that the flattened segment is aligned with the dimple. In this manner, the dimple does not substantially interfere with insertion of the projection into the bore. The projection is inserted into the bore until the dimple is laterally aligned with the groove. The groove is radially tapered such that a wall of the groove defines a minimum diameter proximate the flattened segment and defines a maximum diameter at a location on the projection offset circumferentially from the flattened segment. The male portion is rotated with respect to the female portion such that the dimple cams above or along the groove. The spiral-like configuration of the groove draws the dimple, and thus the female portion, proximally along the projection as the dimple cams along the groove. As the dimple moves proximally along the projection, the male portion is drawn towards the female portion. Once the dimple has moved along the groove from the flattened segment to the maximum diameter location of the groove, the projection of the male portion is secured within the bore of the female portion. Thus, the camming action of the dimple along the groove pulls the male portion and the female portion tightly together.
In order to facilitate the camming action of the dimple within the groove, a slot is operatively associated with the groove and extends diametrically along and longitudinally through a section of the projection. The slot is offset about 15 degrees clockwise from a lateral midline of the projection. When the dimple cams within the groove, compressive forces are generated on the projection, which cause the slot to contract. This contraction can generate a spring force which can pull the male and female portions together, and which can facilitate subsequent disconnection of the male and female portions. However, when the dimple reaches the maximum diameter location, the compressive forces generated by the dimple are directed essentially parallel to the slot. By directing the forces essentially parallel to the slot, the compressive forces may have difficulty in contracting the slot. Thus, the relative dispositions of the slot and the dimple can lead inefficient contraction of the slot, thereby making repeated connection and disconnection of the male and female portions more troublesome.
To disconnect the joined male and female portions of the cable connector, the male portion is rotated in an opposite direction with respect to the female portion such that the dimple reverses its direction along the groove until the dimple again reaches the flattened segment. The dimple is essentially free of the groove at this point. An axially directed force applied to the male and/or the female portions may facilitate disconnection thereof.
While this cable connector may be effective in some circumstances, it has a number of characteristics which may make its performance suboptimal in other circumstances. Specifically, this cable connector may be relatively susceptible to problems caused by manufacturing tolerances. For instance, the dimple is formed on the female member by a stamping process. The stamping process is an additional step in the cable connector manufacturing process, and may incorporate certain irregularities which can compromise the effectiveness of the cable connector.
The nature of the stamping process can make it difficult to predetermine and insure uniformity of the length, width, and depth of the dimple on various female portions. Furthermore, inconsistencies in the composition of the material comprising the female portion may also lead to variances in dimple structure. Additional factors, such as material blank tolerance variation, clamp fixture wear, stamp press tonnage variation, and stamping die wear may contribute to the difficulties in producing a dimple of a uniform, predetermined configuration. This may compromise the effectiveness of the cable connector, and may reduce the electrical conductivity of the cable connector.
In addition, the dimple may wear or deform upon repeated connections and disconnections. Because the dimple is an integral part of the female portion, sufficient wear of the dimple may necessitate replacement of the entire female portion of the cable connector. This can become quite expensive, especially upon consideration that the difficulty in insuring uniformity of dimple configuration may further complicate replacement of the female portion, viz. the dimple on the selected femme portion must be compatible with the male portion already installed on the cable. Alternatively, both the male and female portions may be conjointly replaced.
In order to reduce the probability of electrical shock, insulating members are provided. The male and female portions are each mounted in their own insulating member to facilitate connection and disconnection of the male and female portions. To mount the conductive portions in their respective insulators, screws are provided. Thus, to assemble the male and female portions, the additional steps of inserting and tightening the screws to secure the insulating members to the male and female portions are required.
Given these drawbacks, among others, presented by at least some of the prior art cable connectors, it is desirable to have an improved cable connector which is not susceptible to those drawbacks. The present invention is intended to offer such an improvement.